The standard practice of a 6-8 cycle chemotherapy induction followed by maintenance wasn't a deliberate trial design. It evolved organically from patient intolerance to cumulative toxicities like neuropathy, a limitation newer, less toxic drugs like TDXD don't necessarily share.

A patient's disease stage fundamentally changes their risk calculus. In the metastatic setting, where the primary goal is survival, patients willingly endure significant toxicity as long as their cancer is controlled. In the adjuvant (curative) setting, the long-term impact of that same toxicity becomes a more critical factor.

An ADC may show better response rates than chemotherapy, but its true benefit is compromised if toxicities lead to treatment discontinuation. As seen with failed PARP/IO combinations, if patients cannot tolerate a drug long enough, the regimen's overall effectiveness can become inferior to standard therapy.

Even if randomized trials show zongertinib's efficacy is merely comparable to chemoimmunotherapy, its significantly milder safety profile—especially its lack of cardiac toxicity and manageable side effects—is expected to make it the preferred first-line choice. Patient quality of life and tolerability are becoming decisive factors in treatment selection.

While a small risk of fatal toxicity like interstitial lung disease (ILD) from T-DXd is often accepted in metastatic disease, it's a major concern in the early-stage, curative setting. The ethical bar for safety is much higher when the goal is to cure, making oncologists more cautious about adoption despite efficacy.

The 'safety first' mandate in drug development is flexible. For cancers like leukemia with high cure rates, highly aggressive therapies with severe side effects are deemed acceptable. The risk-benefit calculation shifts dramatically when a cure, not just management, is the goal.

The INTERACT trial showed carboplatin/paclitaxel had similar response rates and PFS to cisplatin/5-FU. It became the standard of care primarily due to its significantly better side effect profile, with lower rates of bone marrow suppression, fatigue, and GI toxicity.

Unlike most cancers, National Comprehensive Cancer Network (NCCN) guidelines recommend clinical trials as the preferred first-line treatment for glioblastoma patients with good performance status. This rare recommendation highlights the dismal outcomes with existing therapies and the urgent need for therapeutic innovation.

The TRILINX trial revealed Xevinapant's toxicity was so high that it forced reductions in standard, effective treatments like cisplatin and radiation. This compromised the foundational therapy, leading to worse patient outcomes and demonstrating a key risk in adding novel agents to established regimens.